The invention relates to treating a fiber web. Especially the invention relates to a device for applying treatment substance for treating a moving fiber web on at least one surface of the fiber web, especially a device for applying treatment substance for treating a moving fiber web, with a nozzle having a channel for the treatment substance, leading to a tip of the nozzle and an opening providing a treatment substance spray, which nozzle has a tip groove area adjacent to the treatment substance opening.
In WO publication 2006/058961 A1 is disclosed a method and arrangement for processing a paper or board web or similar fiber web. In this prior art method a processing mixture is spread on the surface of the web with spray nozzles. In the method the web to be processed is lead from a press nip and between rolls in this nip. Before the web enters the nip such an amount of processing mixture is spread onto at least one side of the web that the processing mixture is still wet when it enters the nip. In the prior art arrangement according to this publication the arrangement comprises at least one press nip, elements for taking the web to the press nip and elements for spreading the processing mixture and the element for spreading the processing mixture are spray nozzles which are arranged at an adjustable distance in the arrival direction of the web from the press nip to feed the processing mixture to at least one surface of the web.
In publication WO 02/072953 is disclosed an assembly for treating a moving web of paper or board with a web treatment substance which assembly comprises an application chamber located in a close vicinity of the moving web and facing the web, whereby the chamber is delineated by the web, the walls of the coater apparatus and sealing means and at least one linear nozzle array incorporating at least one nozzle for spraying the web treatment substance on the web and in which assembly also comprises a suction chamber adapted to communicate with the application chamber and means for removing mist and accumulations of the web treatment substance by way of establishing a flow in the suction chamber and the application chamber.
In FI utility model registration 9401 is disclosed a device for treating a fiber web, which comprises an application device, in particular a spraying device, for applying treatment substance on a moving fiber web, which application device comprises an application chamber and a channel for removing mist of the treatment substance from the application chamber and flow openings for blowing steam and/or air.
In WO publication 2007/006861 is disclosed a moistening nozzle, which comprises a frame to which air and water are fed. Inside the frame there is arranged a water nozzle wherewith the water is conducted to an outlet of the moistening nozzle. The air nozzle comprises means that bring the air into a swirling motion and a sleeve part having an opening through which the air is discharged and in said opening there is arranged a piece that is an integral part of the moistening nozzle frame, whereby the inner edge of the air gap formed by said piece and the sleeve part is provided by the moistening nozzle frame.
In U.S. Pat. No. 6,866,207 is disclosed an atomizer for paper making comprising elongated tubing, an intake orifice disposed on one end of said tubing, a nozzle assembly affixed to the opposite end of said tubing, a first nozzle element extending from said nozzle assembly at an angle with respect to the axis of said tubing, a swirl wheel and cone former concentrically disposed with respect to said tubing and adapted to receive propellant gas from said first nozzle element, and said cone former comprising a swirl ledge angled inwardly with respect to said axis of said tubing. This apparatus creates a continuous seamless spray of the desired liquid using the nozzle utilizing any single gas, steam, air or a mixture thereof as a motive gas or propellant.
In U.S. Pat. No. 6,969,012 is disclosed an atomizer for paper making comprising a housing, said housing having three inlets, three channels each including a nozzle in communication respectively with said inlets, said three inlets comprising a fluid-receiving first inlet, a fluid-receiving second inlet, a liquid-receiving third inlet, one of said channels being the innermost channel, said innermost channel being associated with said third inlet, the one of said nozzles associated with said innermost channel extending outwardly of said housing beyond the other two of said nozzles, and said innermost channel being uniform in diameter from said liquid-receiving third inlet to the outer end of said nozzle.
In WO publication 2005/040497 A1 is disclosed a device for treating a fiber web, especially a device for applying treatment substance for treating a moving fiber web on at least one surface of the fiber web, which device comprises at least one nozzle comprising a channel for the treatment substance and a tip or end of the nozzle for providing a treatment substance flow on the fiber web. The tip or end of the nozzle of the device for treating a fiber web is provided with means comprising insulation means and/or cooling means for managing the temperature of the tip or end of the nozzle.
One problem that may occur in connection with nozzles for applying heated treatment substance on the web in prior art devices for treating a fiber web is that some treatment substance may adhere at the tip or end of the nozzle due to the high temperature of the tip or end of the nozzle and thus disturb the flow of spray of the treatment substance causing an uneven application result. In worse cases the adhered substance amount is high and it may form lumps at the tip or end of the nozzle which lumps might drop on the fiber web causing a break or adhesion of fiber web reel-layers in connection with reeling.